Composite textile yarns



3,034,279 CGMPOSiTE TEXTILE YARNS Alexander Henderson Gentle, Spondon,and Alfred Richmond, Derby, England, and Norman James Tunstall,

Fiint, North Waies, assignors to British Celanese Limited, London,England, a British company No Drawing. Filed Dec. 3, 1958, Ser. No.777,840 Claims priority, application Great Britain Dec. 19, 1957 1Claim. (Cl. 57-157) This invention relates to composite textile yarns.

The object of the invention is to provide a novel type of compositeabrasion-resistant yarn which is of particular use as a pile yarn in themanufacture of carpets.

According to this invention a composite yarn is obtained by twistingtogether (a) one or more continuous filament viscose rayon yarns whichare all twisted in the same direction and (b) one or more continuousfilament yarns of difierent material which are all twisted in theopposite direction from that of the viscose rayon yarns, the directionof the twisting together being in the direction of the twist of theviscose rayon yarns thereby producing a composite yarn composed of yarnshaving different degrees of twist, in the same direction and the viscoserayon yarns being twisted more than the other yarns, bulking thecomposite yarn by passing it through a turbulent zone produced by a highvelocity fluid jet, preferably a high velocity steam jet, and collectingthe yarn at a speed which is less than the speed at which the compositeyarn is fed to the high velocity fluid jet. The yarn may conveniently becollected on a coming machine or in a can for subsequent coming.

The yarns used for one component in this invention are continuousfilament viscose rayon yarns twisted in the same direction which may beeither 8 or Z twist. The yarns used for the other component may be ofcontinuous filament cellulose acetate yarns, either secondary diacetateor triacetate yarns, twisted in the direction which is opposite to thatin the continuous viscose rayon yarns. One or more ends of each type ofyarn may be used. The two types of yarn are then twisted together in thedirection of the viscose rayon yarns so that the twist in the viscoserayon yarns is increased and the twist in the other yarns is first takenout and then inserted in the twisting direction. As an actual example, anumber of viscose rayon yarns having a 3 t.p.i. (turns per inch) 8 twistmay be twisted together using 3.5 t.p.i. S twist with a number ofacetate yarns having 1 t.p.i. Z twist. In the composite yarn the viscoserayon yarns have 6.5 t.p.i. S twist and the acetate yarns 2.5 t.p.i. Stwist.

The composite twisted yarn is then subjected to a bulking process of thetype in which the yarn is fed into a turbulent zone formed by a fluidjet. Such a process is described in the Breen Patent No. 2,783,609. Theform of jet having a resonance chamber as described in US. Patent No.3,010,270 to Richmond ,et al. dated November 28, 1961, may be used withadvantage in carrying out the bulking step of this invention. In thetype of bulking process using a fluid jet, the yarn is usually over-fedinto the fluid jet, that is to say the rate of collection of the yarn isless than the rate of feed; in bulking the composite yarn in the processof this invention an over-feed is used. The actual amount of over-feedwill depend to some extent on the number and types of yarn being treatedand experiments may be necessary to determine the optimum over-feed inparticular cases. Air may be used as the fiuid medium for the jet but,as indicated above, it is preferred to use steam for this purpose.

The abrasion resistance of yarns produced by this invention isappreciably greater than that of corresponding mixed yarns spun onconventional systems.

' tet 3,034,279 Patented May 15, 1962 3 ends or" 750 denier, 50 filament(continuous) secondary acetate yarns having 1.0 t.p.i. Z twist and 5ends of 500 denier, 50 filament (continuous) viscose rayon yarns having3.0 t.p.i. S twist were folded together with 3.5 t.p.i. S twist. Thefolded yarn has 6.5 t.p.i. S twist in the viscose rayon yarns and 2.5t.p.i S twist in the acetate yarns.

The yarn was then passed at a speed of 70 metres per minute through ajet constructed in accordance with US. Patent No. 3,010,270 to Richmondet al. dated November 28, 1961, and supplied with steam at lb. persquare inch; the over-feed was 1.61 to l. The bulked yarn was collectedon a coming machine.

The yarns obtained were tufted on a inch gauge tufted carpet machineusing 9 stitches per inch and a tuft length of 0.8 inch, the carpetbeing backed with a standard latex composition. The resistance toabrasion was measured on the Wool Industries Research Associationscarpet wear testing machine using standard cross-bred wool fabric as theabradant under a pressure of 8 lb. The wear was assessed by examiningthe samples after every 500 revolutions and noting the number ofrevolutions before the hessian back began to show through the pile.

Using yarns made according to the above example the number ofrevolutions over a number of trials varied between 8,500 and 11,500. Asimilar blend of yarns, linen spun to 3/8.1s lea, tufted at 10 stitchesper inch gave figure of 1,500 to 3,000. A percent wool yarn, 2/50sDewsbury, tufted at 9 stitches per inch, gave figures of 2,000 to 4,000.Other corresponding figures for comparison are that with exactly thesame construction and procedure given in the example but using (a) allacetate yarns the abrasion figure was 4,000, and (b) all viscose rayonyarns the abrasion figure was 6,000. In a further construction in whichthe only modification was that the twist of the viscose yarns was 1t.p.i. 2 instead of 3.5 t.p.i. S, the abrasion figure was 4500; in thiscase the direction of twist of the viscose rayon and acetate yarns wasthe same and the abrasion resistance was appreciably lower than that ofthe yarn of the example where the twists were of opposite directions.

The construction described in the example may be modified in a number ofways. For example combinations other than 5 ends of the viscose rayonyarns and 3 of the acetate yarns may be used; thus 2, 3 or 4 ends ofviscose rayon may be folded with 2 or 4 ends of acetate. In addition theacetate yarns may be replaced by continuous filament nylon yarns.Modifications may also be made in the degrees and direction of twistprovided that the non-viscose yarns used are twisted in the directionopposite to the direction of twist of the viscose yarns and that thedegree of twist used in folding the yarns together is suflicient firstto untwist and then to re-twist the non-viscose rayon yarns.

What we claim is:

A process for the production of a composite, abrasionresistant yarnsuitable for use as a pile yarn in the manufacture of carpets whichcomprises twisting together (a) from 2 to 5 continuous filament viscoserayon yarns which are all twisted in the same direction, and (b) from 2to 4 continuous filament cellulose acetate yarns which are also alltwisted in the same directionbut which direction of twist is opposite tothat of the viscose rayon yarns, the direction of the twisting togetherof the viscose rayon yarns and of the cellulose acetate yarns being inthe direction of the twist of the viscose rayon yarns and of such amagnitude that the composite yarn is composed of direction and theviscose rayon yarns a being twisted more than theacetate yarns b,bulking the composite yarn by passing it through a turbulent zoneproduced by a high velocity fluid jet and collecting the resultant yarnat a speed which is less than the speed at which the composite yarn isfed to the high velocity fluid jet.

References Cited in the file of this patent UNITED STATES PATENTS BreenJan. 20, 1959 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTIONPatent No. 3,034,279 May 15 1962 Alexander Henderson Gentle et a1.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent shouQLd read ascorrected below.

Column 2, lines 50 and 51 strike out "In addition the acetate yarns maybe replaced by continuous filament nylon yarns.

Signed and sealed this 25th day of September 1962.

(SEAL) Attest:

DAVID L. LADD ERNEST W. SWIDER Commissioner of Patents Attesting Officer

